Flat panel displays are welcomed by people due to their advantages of lightness, thinness, power saving and the like, wherein liquid crystal display panels are most common. The liquid crystal display panels mainly include the following types according to working modes of liquid crystals: TN (Twisted Nematic) type, IPS (In-plane Switching) type, FFS (Fringe Field Switching) type and the like. The FFS liquid crystal display technology is proved to be a good liquid crystal display mode used for high resolution and wide viewing angle, and characteristics of this mode exceed those of a horizontal electric field driving IPS mode in the same type, because the number of liquid crystal domains can be freely designed to be even or odd in fringe field display, and this kind of design gets rid of the limitation that the number of liquid crystal domains in the horizontal electric field driving IPS mode is even, and thus has an excellent display effect for high-resolution liquid crystal display.
FIG. 1 is a top view of a structure of pixels of an FFS-type liquid crystal display panel in the prior art, and FIG. 2 is a cross-section view of the structure in FIG. 1 along AA′. It can be seen from FIGS. 1 and 2 that the FFS-type liquid crystal display panel includes: a plurality of scan lines 101; a plurality of data lines 102 insulated from and intersecting (generally perpendicularly intersecting) the scan lines 101; and pixel units located in pixel areas (shown by the dashed box in the figure) defined by adjacent scan lines 101 and adjacent data lines 102. Each pixel unit includes a common electrode 104 and a pixel electrode 105 stacked and insulated from each other. The common electrode 104 is flat shape; and the pixel electrode 105 is comb-like shape and includes a plurality of strip electrodes. The pixel unit further includes a TFT (Thin Film Transistor) 103 arranged near the intersection of the scan line 101 with the data line 102, where the gate electrode of the TFT 103 is electrically connected with the scan line 101, the source (or drain) electrode of the TFT 103 is electrically connected with the data line 102, and the drain (or source) electrode of the TFT 103 is electrically connected with the pixel electrode 105. In the pixel structure shown in FIGS. 1 and 2, the pixel electrode 105, the common electrode 104 and the data line 102 are insulated from each other, but for brevity, insulating layers arranged between any two of them are not drawn in the figures. In addition, in the pixel structure shown in FIGS. 1 and 2, the pixel electrode 105 is located above the common electrode 104. The pixel structure further includes a shielding electrode 106 extending from the flat shaped common electrode 104 and covering the data lines 102.
FIG. 3 is a top view of a structure of pixels of another FFS-type liquid crystal display panel in the prior art, and FIG. 4 is a cross-section view of the structure in FIG. 3 along BB′. Similarities between the pixel structure shown in FIGS. 3 and 4 and the pixel structure shown in FIGS. 1 and 2 are not repeated, and differences between them are mainly described. It can be seen from FIGS. 3 and 4 that the common electrode 104 is comb-like shape and includes a plurality of strip electrodes; and the pixel electrode 105 is flat shape. The common electrode 104 is located above the pixel electrode 105. The pixel structure further includes a shielding electrode 106 extending from the comb-like shaped common electrode 104 and covering the data lines 102.
In the pixel structures of the two above-mentioned FFS-type liquid crystal display panels in the prior art, all the pixels are identical in shape and size, which brings difficulty in the design of small-size panels with high-resolution pixels. Specifically, due to the resolution limitation of an exposure machine, there would be minimum design requirements on the widths (namely line widths) of strip electrodes (common electrode, shielding electrode and pixel electrode) and on the spacing (line distance) of slits between the strip electrodes, so that the selection of the number of liquid crystal domains in a pixel in the actual FFS-type liquid crystal display panel is limited. For example, PPI (Pixel Per Inch) of a 5.3 HD (High Definition) product reaches about 280, and each pixel can only include 3 slits at most. If a design that each pixel has more than 3 slits, such as 4 slits, is selected, then the line width and the line distance will exceed the resolution limitation of the exposure machine. In the pixel design of 3 slits, due to the overlarge spacing (line distance) of the slits, the transmittance is reduced; and if a design that each pixel has less than 3 slits is further adopted, then the spacing (line distance) of the slits is further increased, and thus the transmittance will further be reduced.
To solve the above-mentioned problem in the prior art that the number of slits or the number of liquid crystal domains is limited in the FFS pixel design, a pixel structure of a third FFS-type liquid crystal display panel is provided in the prior art, which is shown in FIGS. 5 and 6. FIG. 5 is a top view of a structure of pixels of the third FFS-type liquid crystal display panel in the prior art, and FIG. 6 is a cross-section view of the structure in FIG. 5 along CC′. Similarities between the pixel structure shown in FIGS. 5 and 6 and the pixel structure shown in FIGS. 1 and 2 are not repeated, and differences between them are mainly described. It can be seen from FIGS. 5 and 6 that pixels are different in size due to different numbers of slits in adjacent pixel units; and the two adjacent pixel units have an odd number of strip electrodes and slits in the width direction. Specifically, pixel units 11 and 12 are adjacent, three strip electrodes and two slits are arranged in the pixel unit 11, and four strip electrodes and three slits are arranged in the pixel unit 12; and the width of the pixel unit 12 is greater than that of the pixel unit 11 (the width direction is perpendicular to the extending direction of the strip electrodes).